Free speech does not mean "I can say whatever I like, wherever I like, and nobody can stop me". If you come into my house and start making racist or homophobic comments, I will ask you to leave. Same thing with Shetlink. This is a private space and offers no guarantee of "free speech", however you define that.
We aim for it as far as possible, but there are many reasons why a comment may require moderation. Some decisions will be better than others (we're only human), but the argument of "free speech" is just not relevant. Any comment may be removed for any reason, without explanation, and that's just how it is. We'd prefer not to, but sometimes it's necessary.
Anyway, this topic is about Vaccination cards and has long since drifted off. Feel free to start a topic on free speech though. We may well already have one.